NUCLEAR DATA FOR STUDIES OF REACTOR SAFETY AND CONTROL AND FOR CRITICALITY STUDIES
UKAEA Winfrith Atomic Energy Establishment
Dorchester, Dorset DT2 8DH, UK
The accuracies of predictions of reactivity coefficients, and control absorber reactivity worths, and of criticality, and the status of the nuclear data upon which these predictions depend, are reviewed. Nuclear data adjustments which have been made in some countries in order to improve agreement between measured and calculated thermal reactor reactivity coefficients are described and the consistency of these with recent differential measurements and other evidence is discussed. Measurements used for validating predictions of fast reactor Doppler and sodium voiding reactivity coefficients and control rod reactivity worths are summarised. The agreement between measurement and calculation and the current accuracies of predictions are discussed. The assessment of the accuracy of criticality calculations relating to the fabrication, storage, transport and reprocessing of fuel is usually based on comparisons of calculations with benchmark measurements. The agreement between calculation and measurement, current discrepancies and the accuracy which can be obtained in such criticality calculations is discussed.